Kiwi plant named ‘Bruce’

ABSTRACT

A new and distinct kiwifruit variety is described. The variety results from selection among a population of seedlings derived from a controlled pollination crossing the kiwifruit varieties known as ‘Hort16A’ (U.S. Plant Pat. No. 11,066) and an unreleased selection CK39_16 (not patented). The new variety is a male plant which flowers in a period well-synchronized for pollination of the female variety ‘Hort16A’ (U.S. Plant Pat. No. 11,066). The new variety is characterized by the timing of flowering, distinctive red/brown hairs evident on young shoots and the underside of young leaves. The new variety appears suitable for use as a pollinizer in commercial kiwifruit production and has been named ‘Bruce’.

Latin name of the genus and species of the plant claimed: Actinidiachinensis.

Variety denomination: ‘Bruce’.

BACKGROUND AND SUMMARY OF THE INVENTION

Kiwi plants in cultivation are mainly varieties of A. deliciosa,particularly ‘Hayward’ although some A. chinensis and A. argutavarieties are grown. A. deliciosa and A. chinensis are closely relatedand varieties of both types have large fruit (˜100 g) with hair on theskin. The main varieties in New Zealand are ‘Hayward’ (A. deliciosa) and‘Hort16A’ (A. chinensis). Fruit are usually cut and eaten with a spoon.

All Actinidia species are dioecious, so female varieties have to beinterplanted with male pollinizers to ensure fruit production.

A. chinensis vines are deciduous and tend to grow vigorously in springand summer when rapidly-growing shoots can intertwine and tangle if notmanaged. Vines do best in a mild warm-temperate climate without latespring or early autumn frosts. They produce consistently heavy cropswhen grown in well-drained fertile soils and given regular irrigation indry spells.

A. chinensis flowers in the spring (mid October-early December) in NewZealand. Harvest of A. chinensis fruit may occur between April andlate-May in New Zealand depending on the selection and location ofplantings.

Efficient pollination of female kiwifruit varieties influences seednumbers, which in turn influences fruit size and dry matter. Inselecting new kiwifruit pollinizers the focus is on traits to enhanceefficient pollination including pollen viability, pollen yield, numberof flowers produced, and synchronization of the release of pollen frommale flowers at the same time as the female flowers are receptive. A lowvigor cultivar is preferred to minimize pruning costs.

The new variety was selected from a population of seedlings derived froma controlled pollination crossing of the kiwifruit varieties known as‘Hort16A’ (U.S. Plant Pat. No. 11,066) and an unreleased selectionCK39_(—)16 (not patented) after observations of character andperformance carried out from 1999 to 2000. The patented female parent‘Hort16A’ was bred and selected in New Zealand, U.S. Plant Pat. No.11,066. The unpatented male parent CK39_(—)16 was selected in NewZealand from seedling plants raised from an introduction ofopen-pollinated seed from an un-patented parent from China in 1989. Thisnew variety was created during the course of a planned plant-breedingprogram, which was initiated during 1995 in Te Puke, New Zealand. Thecross was made on Oct. 29, 1995 in Te Puke, New Zealand. Seeds were sownin the spring of 1996 and 80 seedlings from this cross were planted outin the field at Te Puke in 1997. The selection ‘Bruce’ first flowered inOctober 2000. Selection ‘Bruce’ was grafted in 2000 onto five existingkiwifruit rootstocks at Te Puke, in a clonal selection trial plot, usinggraft wood from the original seedling plant.

The new variety was selected from among plants located on land at TePuke, New Zealand, and was assigned the breeder code, 32-01-13a. The newvariety has since been named ‘Bruce’.

The present invention is a new and distinctive kiwifruit male varietywhose flowering period coincides well with the patented female kiwifruitplant ‘Hort16A’ in most districts where kiwifruit are grown in NewZealand.

The new variety can be asexually reproduced as cuttings or by graftingor budding on to seedling or cutting-grown rootstocks of A. deliciosa orA. chinensis. Trial plantings of grafted plants established at Te Puke,Nelson and Kerikeri in 2003 have shown that the unique combination ofcharacters come true to form and are established and transmitted throughsucceeding asexual propagations.

The new variety is characterized as follows:

-   Plant ploidy: Diploid.-   Plant form and vigor: A twining habit, with strong vigor, similar to    ‘Hort16A’ (U.S. Plant Pat. No. 11,066); the surface of the dormant    cane is smooth and a white bloom is present; distinctive red/brown    hairs are evident on the young shoots and the underside of young    leaves.-   Foliage: The mature leaf is broad ovate in shape; the upper surface    of the leaf is smooth; the lobes of a mature leaf are arranged    slightly overlapping.-   Flower: The number of flowers in each inflorescence is typically    between one to four flowers, with each inflorescence comprising a    single king flower and one or two side flowers; the single colored    petal is absent of any red blotch which is sometime present on the    petals of flowers of other male varieties, for example ‘Meteor’ (not    patented).-   Time of flowering: Early.-   Plant health: No visible leaf symptoms have been observed indicating    the plant is not virus-infected. Resistance to pests and disease is    unknown.-   Pollination efficiency: The new variety was initially selected on    the basis of its potential for synchrony of flowering with the    commercially important New Zealand female kiwifruit variety    ‘Hort16A’ (U.S. Plant Pat. No. 11,066) and the resulting large fruit    size of fruit of ‘Hort16A’ (U.S. Plant Pat. No. 11,066) after hand    pollination with excess pollen. Subsequent trials indicate that    flowering of the new variety does appear to be well synchronized    with when female flowers of the variety ‘Hort16A’ (U.S. Plant Pat.    No. 11,066) are receptive in many production areas in New Zealand.    Observations of the performance of the new variety indicate it has    potential to bring about improved yield from ‘Hort16A’ (U.S. Plant    Pat. No. 11,066) relative to other male pollinizers currently used    commercially in New Zealand such as ‘Meteor’ (not patented) and    ‘Sparkler’ (not patented) due to better coincidence with ‘Hort16A’    (U.S. Plant Pat. No. 11,066) flowering, and good ability to    influence fruit size when pollen is delivered to the female flowers.    Key attributes of the new variety in this regard include good pollen    viability, and a high pollen yield, in combination with a medium    flower load per plant (measured as the number of flowers per meter    cane).

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures show typical specimens of the plant, foliage,and flowers of the new variety as depicted in colors as nearly true asis reasonably possible in a color representation of this type.

FIG. 1 shows a plant of the variety ‘Bruce’ in the field; view is offlower buds, open flowers, and new leaves.

FIG. 2 shows an inflorescence of the variety ‘Bruce’; view is of flowerbuds, open flowers, and pedicel.

FIG. 3 shows the tip of a new shoot of the plant of the variety ‘Bruce’;view shows the typical red coloration on the young shoot of ‘Bruce’.

FIG. 4 shows a fully expanded leaf of the plant of the variety ‘Bruce’.

FIG. 5 shows a typical vine of the variety ‘Bruce’.

FIG. 6 shows typical flowers and buds of the variety ‘Bruce’.

DETAILED BOTANICAL DESCRIPTION

The following is a detailed description of the new variety. The newdiploid kiwifruit variety ‘Bruce’ is staminate (male), produces onlymale flowers, and no fruit.

Horticultural terminology is used in accordance with UPOV guidelines forkiwi. All dimensions are in millimeters, and all weights are in grams(unless otherwise stated). Certain characteristics of this variety, suchas growth and color, may change with changing environmental conditions(e.g., light, temperature, moisture), nutrient availability, rootstocks,or other factors. Color descriptions and other terminology are used inaccordance with their ordinary dictionary descriptions, unless thecontext clearly indicates otherwise. Color names beginning with acapital letter designate values based upon The Royal HorticulturalSociety Colour Chart published by The Royal Horticultural Society,London, England.

TABLE 1 CHARACTERISTICS ‘Bruce’ PLANT (Measurements from samples of 10,unless stated otherwise) Plant: sex expression Male Plant: ploidyDiploid Plant: vigour Vigorous Young shoot: hairs Present Young shoot:density of hairs Dense Young shoot: type of hairs Tomentose Young shoot:anthocyanin coloration Medium of growing tip Young shoot: anthocyanincoloration Present of leaf axil STEM Stem: coloration of leaf axilAbsent or very weak Stem: diameter Mean: 10.58 mm, Range: 8.7 mm-13.8 mmStem: length Mean: 1.5 m, Range: 1.2-2.0 m Stem: dormant bud diameterMean: 7.96 mm, Range: 6.9 mm-9.9 mm Stem: color on upper side of dormantGrey-brown, R.H.S. 200C shoot Stem: character of bark Smooth Stem: hairsPresent Stem: conspicuousness of lenticels Conspicuous Stem: number oflenticels/cm² bark Mean: 4.0 lenticels, Range: 2.5-5.4 lenticels Stem:color of lenticels Orange-brown, R.H.S. 177C Stem: size oflenticels-length Mean: 2.34 mm, Range: 1.3 mm-3.5 mm Stem: size oflenticels-maximum Mean: 1.67 mm, Range: width 0.71 mm-2.08 mm Stem: sizeof bud support Mean: 4.9 mm, Range: 4.0 mm-5.9 mm Stem: visibility ofbud (dormant Visible canes) Stem: number of hairs visible on bud Many(dormant canes) Stem: presence of pith Present Stem: type of pithLamellate LEAF (Mature) Leaf: general shape of blade Very broad ovateLeaf: length Mean: 144 mm, Range: 124 mm-164 mm Leaf: width Mean: 161mm, Range: 138-185 mm Leaf: petiole length Mean: 158 mm, Range: 90-192mm Leaf: ratio leaf length to width 0.90 Leaf: ratio leaf length topetiole 0.91 length Leaf: shape of tip of blade Acute Leaf: shape ofbase of blade Cordate Leaf: arrangement of leaf bases Slightlyoverlapping Leaf: puckering/blistering on upper Weak side of blade Leaf:margin Ciliate Leaf: green color of upper side of Medium green, R.H.S.137A blade Leaf: glossiness of upper surface Medium glossy of bladeLeaf: color of lower side of blade Light green, R.H.S. 137C Leaf:glaucosity (lower side of blade) Absent Leaf: hairs on petiole PresentLeaf: density of hairs on petiole Dense Leaf: anthocyanin coloration onWeak upper side of petiole FLOWER Inflorescence: predominant number 3 offlowers Flower: pedicel hairs Present Flower: pedicel, length of hairsVery short Flower: pedicel length Mean: 36.7 mm, Range: 30.3 mm-45.2 mmFlower: number of sepals 5 to 7 Flower: color of sepals Yellow-green,R.H.S. 195A/147C Flower: length of sepals Mean: 6.23 mm, Range: 5.08mm-7.65 mm Flower: diameter of sepals Mean: 4.65 mm, Range: 3.69 mm-6.01mm Flower: diameter (terminal or king Mean: 36.2 mm, Range: flower whenfully open) 25.3 mm-40.7 mm Flower: mean number of petals per Mean: 6.8petals, Range: 5-9 petals flower Flower: length of petals Mean: 16.43mm, Range: 14.5 mm-18.0 mm Flower: width of petals Mean: 15.24 mm,Range: 12.8 mm-18.1 mm Flower: ratio petal length/width 1.15 Flower:arrangement of petals Overlapping Flower: petal curvature of apexStrongly expressed Flower: primary color of petals White, R.H.S. 158D(when fully open) Flower: type of coloration of petals Bi-color Flower:secondary color of base of Green, R.H.S. 146D petals. Flower: filamentcolor Greenish-white, R.H.S. 157A Flower: anther color Yellow/orange,R.H.S. 163A Flower. anther number per flower Mean. 52.2 anthers, Range:37-68 anthers EVENTS Time of vegetative budbreak Early-similar toHort16A female Time of beginning of flowering Early-similar to Hort16Afemale

Observations were made on plants grown at Te Puke, New Zealand. Theseplants had been grafted on to seedling kiwifruit rootstocks.

Rootstocks

‘Bruce’ vines can be grown on the same rootstocks as can ‘Hort16A’.Rootstocks currently being used in New Zealand include A. deliciosa andA. chinensis seedlings, ‘Hayward’ (not patented) and ‘Kaimai’ (notpatented) rooted cuttings.

Flowering and Plant Management

Young vines of ‘Bruce’ flower heavily when young, and most flowersshould be removed from grafts and young plants to allow the plant toestablish a good canopy of canes. Mature plants can be pruned afterflowering by removing up to two thirds of the canopy and allowing newcanes to establish over the growing period. Minimal pruning is done inwinter.

Pest and Disease Resistance/Susceptibility

Pest and disease issues are of minor significance for non-croppingpollinizers, and at this stage we have not recorded any particularsusceptibilities to pests or diseases for this male variety.

Comparison to Closest Cultivar

The distinctive characteristics of this new kiwifruit variety, describedin detail below, were observed in 2007 at Te Puke, New Zealand. The ageof the plants was 7 years from grafting onto seedling rootstocks.

Comparison with similar male varieties, ‘Meteor’ and ‘Sparkler’, incommercial use in New Zealand shows that ‘Bruce’ can be distinguishedfrom these varieties as outlined in Table 1.

TABLE 2 COMPARISON WITH SIMILAR VARIETIES Characteristic Bruce MeteorSparkler Flower: Petal color Absent Present Absent blotch presenceSurface of dormant Smooth Rough Smooth cane Color of hairs on Red/BrownPale Brown Pale red young shoots and leaves White bloom on Present,medium Not present or Present, strong dormant cane expression weakexpression Upper surface of Smooth Rough Smooth leaf to the touch Matureleaf lobe Slightly Overlapping Touching arrangement overlapping Time offlowering in Starts at same Starts up to Starts from relation to time as10 days before 2-7 days after ‘Hort16A’ female ‘Hort16A’ ‘Hort16A’‘Hort16A’

‘Meteor’ and ‘Bruce’ are relatively easy to distinguish in that ‘Meteor’has a rough surface of canes and upper surface of leaves, has a pinkblotch on petals at time of flowering and weak expression of white bloomon dormant canes, whereas ‘Bruce’ has smooth leaves and canes, no pinkblotch on flowers and medium expression of white bloom on dormant canes.‘Sparkler’ and ‘Bruce’ are more similar in appearance overall as bothhave smooth leaves and canes, but ‘Sparkler’ commences flowering up to 7days later than ‘Bruce’ and the young flowering shoots of ‘Bruce’ andthe undersides of young leaves have a much more intense red colorcompared to ‘Sparkler’. In addition, ‘Bruce’ leaf lobes are slightlyoverlapping, while ‘Sparkler’ leaf lobes are touching.

1. A new and distinct kiwi plant as herein described and illustrated,selected from seedlings derived from a controlled pollination crossingof the kiwifruit varieties known as ‘Hort16A’ (U.S. Plant Pat. No.11,066) and an unreleased selection CK39_(—)16 (not patented) andcharacterized by its appearance and flowering period.